Tunnel kiln for ceramic industry



.2 Sheets-Sheet l m w... ,..--..THHAMWHut. .1...-.. --i-\ V. SELLIEZ Filed De. 2, 1925 `ece.. @@@QCCCGCQdQGGOOOOOG TUNNEL `KILH FOR CERAMIC INDUSTRY Sepe. 4, 192s.

Sept. 4, 1928.

V. SELLIEZ TUNNEL` KILN Fox cERAuI-c INDUSTRY 2 sheets-sheet 2 Filed Dehv. 2, 1925 l .m .mam

q imhnmnb Patented Sept. 4, 1928.

UNIT sniffer-aresregisseerarspw'r OFFICE.

4VIC'ro-I; isnjnnmz, ori s'rgvensnarm. BELGIUM'.

Fon CER-Artic 4 rNDUsTPLY.

Appnatin med D''ember'z i925, seran No.' 72,843, andni ABelgium 'Dl-ember 2, i924.

This inventionrelates lto the bakinglr of cerar'fic products andhas 'for' its? objects 1.-A uniform "he'at. i'r'1gl of the articlesto be baked, obtained by con'ductingf and localiziirgl inv theilo'wer lof; thel kiln, a large percentage'of the'burned gases; .2f-The successive andrational coolingr of thai baked etudes,"-'bycamenng the' an; thatv takes their heat offg' tocirciilate* in the upperpa'rt of the'tiinelg 3.-The possibilityiof varvinir.y as desired.Vv the .temperature and `conditi,'onsA 4in the kiln, by j'udicioiislyprpdrtioningth'ecoinbustible gases' and theco'mb'ustion air and deflectinq frorrintheicombustion chamber "a 'lame/part of the fair Lcomingf'fromithe lcoolingr `zone.

-iTuiiiie -kiliis, notwithstanding the, advantages offthei baking'I method, rarely work satisfactorily. l I.

'In' the' later times; there thas v*been a Vtendency to l'draw the"combustion' nroducts'towards thelowerpart-of thekilh. vBut this operation' can lbe .very dangerous for the cool-l ing of the bakedproducts,when the airgused for such cooling', can freely -pass through the same waysas the burned 'gasesf In fact;

when in the coolingr zone, `the cold and heavy air, will of course circulate in thelower part of theikiln-` andthe baked products, because they cannot vcol'by convection with such air. will only lose, a small part of their heat hv radiation, towards the outer walls of the y kiln.

Moreover., such secondary air, enteringr in ,large quantity and at low temperature the zone of combustion will of course strongly lower the required temperature and, simultaneously, oppose any easy modification of the kiln conditions.

Figures 1 and 1a represent the left and right hand portions, respectively` of a tunnel kiln constructed in accordance with the invention, the view being a vertical sectional view.

Figures 2 and 2a are the left and right hand portions, respectively, of the kiln shown at horizontal section.

Figure 3 is an enlarged vertical transverse section.

Figure 4 is an enlarged fragmentary horizontal section correspondingr to Figure Q and showing the floors of several. of the cars in section.

Figure 5 is a fragmentary horizontal section of a modification of the kiln.

It is assumed the working-principles of canals A .forma continuous flue, reaching from "oneextremity of thekiln'ftofthe oppositeone. In lthe 'combustion and pre-'fire zones;y the vault of the kiln .isfstra'ight '(Fig; p '1 '1"' mi, 2 WVithout entering -into details ofthefctim-v bust-ible gases production,"V4 it fis `noted they' pass the' lkiln walls through 'channels 5 lin front of which the"flues c willbeialinedat The cars' being" placedfen'd to cnaf-the cvery'stop'page' of the cars. As soon a's they enter the( kiln` said/gases w'ill'take' thepro portion o'ffcom'bust-iou aiigthey' may'lack.

Owing,r to the high-temperature produced,

the cornbnstior'i products will eXpa-ridljconsiderably; one' partof "sarnewill' follow canal A and escapeto'wards-the chimneytlie `other part. flowing through the dues willfill the' room between thepile, th'e'late'ral' walls and the kiln'vau'lti "I Owing to the rule of stratification according to gravity, vertically directed currents will arise in the whole course of the gases, the cold gases descending towards canal A and the hot ones. ascending to the vault. At last the burned gases drawn in by under pressure, will flow towards the chimney and be sucked in by the flues s, which will be provided with regulation claps.

Before examiningr the conditions of coolin;r of the goods. let us state. that the vault, in this zone. is slopingT from E to G; besides, between the cooling and the fire zones (thus between M N and M N) the spaces between the pile, on one part, and the vault and lateral walis on the other part, will be as much reduced as the free passages of the goods will allow. Now, if the cars, when leaving the fire were to pass directly in the coolingr zone, the secondary air aspirated through E, would merely iow into the canal A, Without carryingr away the heat of the baked `goods; and therefore the arrangement is such that the aperture P between two of the cars, may be closed by a rectangular plate p for obstructingr the canal A.

Said plate maybe withdrawn at P', a short time before taking the cars out.

As the cold air can no longer travel in the cooling zone by passing through the car floor, it is compelled to-flow along the Vlateral walls and through the vault. The stratification processes, as stated above, will produce interchangesof heat between the upper and the lower parts of the kiln and the hot gases, following the vault, will collect in G. The cold air, tlirottled in its passage in the longitudinal direction, owing to the narrowing of the walls towards the pile between M 'Nv and M N', will be aspirated through a Siphon and returnedinto the kiln at the level of the floor-'flues by-channels 1' provided with regulation 4claps and located either between tlie burners, or before or behind the lire, accordngfto the conditions to be obtained, i. e. oxydizing neutral or reducing effects.

The height' and length of the horizontal pipe of the siphon shall be calculated in 1' resistance in such pipe.

accordance with the pressure required for forcing the air down to the lloor level. Alternatively, a given part of the air can be paed directly from the cooling zone to the pre-fire zone, without using the siplion; by forcing saine to pass through a pipe T and to reenter under the vault, the differencel of under-pressure between ints t and t being as a rule,y sullicient or overcoming the It should be noted that the air blown in through the Siphon, at R (between M. N and M^ N will cool the floor, thus making the slipping in of plates p easier.

In case. of a tunnel of reduced length, the travel of the flames could be lengthened by sive parallelopipedon, coveringthe whole area of the cars. But if said cars are very large, the piles maybe separated b y`spaces perpendicular to the furnace axis; ports o (Fig. 4) through the upper partof the floor place canal A in communication with such spaces and with the vault.

In the drawing and description all fea.- turcs relating to the production of combustible gases, as not falling within the scope of this invention. However, whateverinay be tlie class of fuel used (solid, lfluid oi gaseous), it will be evident the siphon may ieadily feed saine wit-li combustion air.

Claim:

In a baking apparatus, a tunnelkiln, cars movable through the kiln, said cars having hollow floors provided with central com; inunicating canals and lateral ductswcommunicating with the canals for receiving combustible gas, and means for admitting combustible gas to said ducts. H

In testimony whereof I have signed my naine to this specification.

vieron SELLIEZ, 

